This invention relates to a pressure equilibrium apparatus for a refrigerator, more particularly to a pressure equilibrium apparatus for a refrigerator which maintains a pressure equilibrium between for a compartment and the ambient atmosphere.
A conventional refrigerator having a reservoir tube for containing defrost water is shown in FIG. 4. A refrigerator comprises a cabinet 1 which forms a body and door(s) 2 which is/are hingedly mounted at the front side of the cabinet 1. Further, a gasket 3 having a magnet (not shown) therein is provided at the door 2 for sealing the gap between the door 2 and the cabinet 1. After the door is closed, a cooling fan adjacent to an evaporator (not shown) is operated to pull the inside air of the compartment toward the evaporator. Because the heat-exchanged air is at a lower temperature, the pressure of the air is relatively lowered. That creates a vacuum inside of the compartment. Owing to the pressure difference between the inside of the compartment and the outside thereof, an additional force corresponding to the pressure difference is required to open the door, which is one problem of the conventional refrigerator.
Meanwhile, to vent the water melted by a frost which surrounds on an evaporator, a venting pipe 4 is provided in which one end of the venting pipe is connected to the inside of the compartment, while other end thereof is connected to the outside of the compartment. The one end of the venting pipe is extended to the vicinity of the evaporator and the other end of the venting pipe is extended to an evaporator dish 6 which is mounted in a machinery chamber 5. Thus, the water melted from a frost or the defrost water is conducted through the venting pipe 4 and collects in the evaporating dish 6 in which the water is evaporated. Further, a U shaped pipe 7 is provided at the middle of the venting pipe to trap a predetermined volume of the defrost water. Due to the presence of the trapped water, a relatively hot air of the outside can not be introduced into the inside of the compartment through the venting pipe, while a relatively cold air inside of the compartment can not discharge to the outside therethrough. The typical arrangement of that apparatus is described in Japanese Patent Laid Open Publication No. 1987-59369 and Utility Model Laid Open Publication No. 1987-60883, respectively.
However, since the air flow between the outside of the compartment and the inside thereof is interrupted by the defrost water trapped in the U shape pipe, above-described problem relating to the the pressure difference can not be solved which occurs when the door is closed. That is, the additional force corresponding to the pressure difference is still required to open the door.